Resveratrol From Transgenic Alfalfa for Prevention of Aberrant Crypt Foci in Mice

Abstract

Transgenic alfalfa (Medicago sativa L.), which accumulated resveratrol-glucoside (RG), was incorporated into diets and fed to female, 6-wk-old CF-1 mice for 5 wk. Mice fed diets containing transgenic alfalfa with supplemented α -galactosidase had significantly fewer azoxymethane (AOM)-induced aberrant crypt foci (ACF) in their colon relative to mice fed the transgenic alfalfa diets without added α -galactosidase (P = 0.02). Resveratrol-aglycone (Rag) was detected in the colon of 100% of mice fed transgenic alfalfa diets with supplemented α -galactosidase and in 60% of mice fed transgenic alfalfa without α -galactosidase (P < 0.05). Colonic concentrations of Rag (< 0.5 nmol/g tissue) in mice fed transgenic alfalfa with α -galactosidase (0.22 ± 0.18 nmol/g tissue) tended to be higher than in animals fed diets without α -galactosidase (0.1 ± 0.08 nmol/g tissue; P = 0.09). The use of N-(Bn-butyl)-deoxygalactonojirimycin, an inhibitor of lactase-phlorizin hydrolase (LPH), in transport studies with everted jejunal sacs from CF-1 mice (N = 8) suggested that LPH is involved in the intestinal deglycosylation of RG. Our collective findings suggest that RG from transgenic alfalfa is metabolized and absorbed in the upper intestine and does not reach the colon in sufficient amounts to inhibit ACF.

ACKNOWLEDGMENTS

This research was funded by grants from the American Institute for Cancer Research (AICR) and the Center for Designing Foods to Improve Nutrition (CDFIN) at Iowa State University. The authors express no conflict of interest related to this research. No on-line material has been submitted with this manuscript. The authors would like to thank Diane Luth for technical assistance; Kim Hammer, Carlie LaLone, and Joe Przybyszewski for their help in collecting animal tissue samples; and Muhammet Sakiroglu and Xuehui Li for helping in the daily maintenance of the alfalfa plants.